Class DisableHotlinkingAttribute.DisableHotlinkingFilter

Authorization filter created by DisableHotlinkingAttribute via TypeFilterAttribute. Resolves IHttpService from the request service container to obtain the application base URL, then compares it against the Referer header to determine whether the request originates from an external domain.

Inheritance

object

DisableHotlinkingAttribute.DisableHotlinkingFilter

Implements

IAsyncActionFilter

IFilterMetadata

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: DataWeb.Filter

Assembly: DataWeb.Core.dll

Syntax

public class DisableHotlinkingAttribute.DisableHotlinkingFilter : IAsyncActionFilter, IFilterMetadata

Remarks

The placeholder image is read from disk on every blocked request. Consider caching the image bytes in memory to avoid repeated I/O under high load.

IHttpService is resolved via GetRequiredService<T>(IServiceProvider) rather than constructor injection because the service lifetime is scoped to the current HTTP request.

Constructors

DisableHotlinkingFilter(IWebHostEnvironment)

Authorization filter created by DisableHotlinkingAttribute via TypeFilterAttribute. Resolves IHttpService from the request service container to obtain the application base URL, then compares it against the Referer header to determine whether the request originates from an external domain.

Declaration

public DisableHotlinkingFilter(IWebHostEnvironment webHostEnvironment)

Parameters

Type	Name	Description
IWebHostEnvironment	webHostEnvironment	Provides access to WebRootPath to locate the placeholder image.

Remarks

The placeholder image is read from disk on every blocked request. Consider caching the image bytes in memory to avoid repeated I/O under high load.

IHttpService is resolved via GetRequiredService<T>(IServiceProvider) rather than constructor injection because the service lifetime is scoped to the current HTTP request.

Methods

OnActionExecutionAsync(ActionExecutingContext, ActionExecutionDelegate)

Intercepts the action execution to enforce hotlink protection. If the Referer header is present and does not match the application base URL, the pipeline is short-circuited and the placeholder image (or 404) is returned. If the Referer is absent or matches the application URL, execution continues normally.

Declaration

public Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)

Parameters

Type	Name	Description
ActionExecutingContext	context	The ActionExecutingContext for the current request.
ActionExecutionDelegate	next	The delegate to invoke to continue the action execution pipeline.

Returns

Type	Description
Task	A Task representing the asynchronous operation.

Implements

IAsyncActionFilter

IFilterMetadata